Valve mechanism



Oct..8, 1940.1v Rfs. SANFORD Er' A1. '2,215,355

' Y VALVE MEGHANISM Filed Aug( 17, 193s Qov S.l Sam-'ono Wuylnm d. ANDRES Patented Oct. 8, 1940 vALvE MECHANISM Roy S. Sanford and William J. Andres, Pittsburgh,

Pa., assignors rto Bendix-Westinghouse Automotive Air Brake Company, Pittsburgh, Pa., a corporation of Delaware Application Angustia, 193s, serial No. 225,434 2 claims (ci. 251-118) This invention relates to control valve mechanism, and more particularly to an improved.

valve mechanism suitable for use with fluid pressure brake systems.

lis A It is often 4desirable in iluid pressure brake systems to control. abrake actuator or set of brake actuators irom different control stations,

and since the control valves used in such apparatus have ports for connecting the actuator with 10 atmosphere when in brake release position, it is necessary to provide a transfer or double check valve in the system so constituted as to prevent the flow of fluid pressure from one control valve to the atmospheric port of the other valve when a. brake application is made by operation oi' the ilrst valve; It is also desirable in many cases to have the fluid exhausted from the actuator through the control valve which originally supplied -iluid to the actuator. and the ,transfer valve should also beso constructed as to avoid leakage and must be incapableoi assuming a poftsition such that on simultaneous brake applying operation of thel control valves the flow of fluid to the 'actuator fromthe control valves will g5 prevented.

It is accordingly one of the objects of the present invention to provide in a simple and 'eiiicient structure a novel transfer valve device which vshall/be so constituted as'to secure the aboveao noted advantages. on

A 'Another objectis to provide a valve device in a system of the above type which will at all times insure a positive application oi' the brakes. Another object is4 to provide in a valve of the above type a structure which shall be subs v tially leak proof during all conditions of o ation thereof.

A still further object is to provide in a fluid4 pressure actuator system-a. transfer valve which o shall berelatively simple in construction as well as economical of manufacture, and atv the same `time be capable of emcient Aoperation over a long periodici service. l V 5 Other objects and novel features of the invention will' appear more fully hereinafter from' the following detailed description when taken in connection with `the .accompanying drawing illustrating a preferred embodiment of the invention. 50 It is to vbe expressly understood, however, that Vthe drawing is employed for purposes oi' illustration only and is not designed as a. definition o f f' the limits of the invention, reference being had vfor,thatplu'posetothe appended claims. In the drawing, wherein similar reference characters refer to like parts throughout the sev' eral views: .I 4 Fig. 1 is a diagrammatic view of'a iluidpressure brake system including a transfer valve device constructed in accordance with the princi- 5 ples of the present invention; f

Fig. 2 is a sectional view oi the valve device illustrated in Fig. 1, and

Fig. 3 is a plan view of the diaphragm and valve assembly of Fig, 2 and is taken along -'line 10 3-3 thereof. y

In the illustrated embodiment of the invention,

'the fluid pressure brake system in general is shown in Fig; 1 'as including a fluid pressure reservoir 5, control valves 6 and l, a transfer or dou- Il ble check valve 8, and fluid pressure operated brake actuators 9 having pistons, not shown, mounted therein and connected to brake operating shafts III by means of piston rods I I, clevis pins I2 and brake levers I3, in a manner well 20 known to those skilled in the-brake art.

As shown in Fig. 2, the valve device 8 has a casing member I4 having an inlet port i5, an inlet cavityl I8, an outlet cavity Il, an outlet port I8, and a communicating port i9 between 25 said cavities which may include a bushing 2l) carried by a bore formed in casing It as shown and having a valve seat portion 2i formed at the right end thereof for a purpose to be more fully described hereinafter.

Another similar casing 30 member 22- is arranged in opposed relationship with casing member I4, and is provided with a similarly disposed inlet port 23, inlet cavity 2l, outlet cavity 25, outlet port 26, and a communieating port 21 between the cavities formed in a 35 bushing 28 carried by casing 22. A valve seat 28 is formed as shown on the left end of the bushing 28.

In assemblingthe valve 8, the members il and 22 are secured together in opposed rela- 40 tionship as by means of bolts 30, the joint bey tween the casing members being sealed by a combined resilient gasket and diaphragm member 3i clamped therebetween. The diaphragm member is provided with a port 32 registering with 45 outlet cavities il and 25 and forms at its central portion a ilexible partition between the inlet cavities i6 and 24, which effectively prevents the direct flow of uid pressure from one cavity to the other. A pair of valve members 3 3 and 34 50 are attached to the diaphragm by meansof a rivet 35 and may be normally held in spaced relationship with their corresponding valve seats 2| and 29 by the diaphragm.

'I'he brake control valves 8 and l, which are preferably of the well known self-lapping type, are connected to the supply reservoir 5 by conduits 36 and 31 and 36 and 38 respectively. Valve 6 has an outlet conduit 39-which is connected to the inlet port I5 of valve 8, and it-will be apparentffrom the foregoing description that under -normal conditions the control valve 6 will be in communication with the actuators 9 through conduit 39, port I5, inlet cavity I6, port I9, outlet cavity I1, outlet port I8, and conduits 40,-4I and 42, conduit 40 being connected to the outlet port I8 of valve 8. In like manner control vvalve 1 is normally connected to the brake actuators 9 through an outlet conduit 43 connected to the inlet port 23 of valve '8,` inlet cavity 24, port 21, outlet cavity 25, and outlet port 26 which is connected to conduit 40 by means of conduit 44, and it is to be pointed out that with valves 6 and 'I in brake releasing position, the actuators 9 are connected with atmosphere by virtue of the fact that the control valves 6 and 1 when in release position serve to connect the conduits 39 and 43 respectively with corresponding exhaust conduits haust conduit 45 and to connect the fluid pressure supply conduit 31 with conduit 39, it Will be apparent that iiuid pressure will be conducted from reservoir 5 to actuators 9 through conduits 36 and 31, control valve 6, conduit 39, port I5, cavity I6, port I9, cavity I1, port I8 and conduits 40, 4| and 42, the uid tending at the same time, by reason of port 32, to ow through cavity 25, port 21, cavity 24, port 23, conduit 43, valve 1 and exhaust conduit 46 to atmosphere, the valve 1 being in release position as heretofore described. Since the diaphragm 3|, however, is of a iiexible nature and is easily moved by small pressure differentials, the pressure of the fluid in inlet cavity I6 acts to move the central portion of diaphragm 3| to the right prior to the build up of a corre.- spondlng pressure on the right side of the diaphragm, thus moving the valve membery 34 against valve seat 29 and eiectively preventing the escape of uid lpressure from cavity 25 to atmosphere through valve 1 in the manner above described. Y

Since the eiective area of -diaphragm 3| is greater than that of valve member 34, it will be noted that when the pressures equalize in out-` let cavities I1 and 25 there will be a corresponding force differential acting to hold valve member 34 on its seat, and that during subsequent brake releasing operation oi' control valve 6, the valve member 34 will be maintained against the seat, thus permitting exhaust of iluid pressure from actuators 9 to atmosphere through conduits 42, 4| and 44, outlet cavities I1 and 25 of transfer valve 8, port I9, inlet cavities I6, inlet port I5, conduit 39, control valve 6 and exhaust conduit 46.

In like manner the control valve 'I may be actuated to connect reservoirl 5 with actuators 9 through conduits 36, 38 and 43, port!! of trans- 2,21e,s55 A fer valve 8, inlet cavity 24, port 21, outlet cavities 25 and I1, ports 26 and I8, and conduits 44, 4| and 42, brake release operation of the valve 1 permitting release of fluid from the actuators to atmosphere through conduits 42, 4| and 44.

outlet cavities 25 and I1, port 21, inlet cavity 24, conduits 43, control valve 1 and conduit 46. It will be readily apparent that control of the brake actuators by valve 1 will cause the diaphragm 3| to move to the left and seat the valve 33, thus effectively preventing the flow of iiuid pressure from valve 1 to atmosphere through control valve 6.V A

With further reference to the foregoing description, 4it is pointed out that the ports I9 and 21 of transfer valve Ill cannot be closed at the same time by their associated valve members 33 and 34, thus preventing the possibility of a brake failure when both control valves are actuated concurrently, and at the same time allowing a control valve, operated to deliver a high pressure to the brake actuators, to actuate the transfer valve 8 to disconnect the actuators from the other control valve operated to deliver a. lower pressure to the actuators.

While the invention has been illustrated and described herein with considerable particularity it is to be understood that the same is not limited to the form shown, but may receive a variety of mechanical expressions as will readily appear to those skilled in the art. Reference will, therefore, be had to the appended claims for a delinition of the limits of the invention.

What is claimed is:

1. A transfer valve comprising a casing having a pair of inl'et ports and a pair of outlet ports.

each in communication with the others, a pressure responsive device in said casing normally permitting communication between all of said 4ports and valve means controlled by said device for interrupting communication between said inlet ports and for selectively interrupting communication between one or the other of said inlet ports and said pair of outlet ports upon introduction into said casing of fluid pressure through said one or said other inlet port.

2. A transfer valve comprising a pair of casing members each having inlet and outlet cavities provided with ports, a port in each member connecting said inlet and outlet cavities, a diaphragm member having a port therethrough, and means for clamping said members together in opposed relationship whereby the diaphragm memberforms a sealing gasket therebetween, the port in said diaphragm connecting said outlet cavities to form a common outlet chamber and the central portion ofthe diaphragm being so located with respect to said.connecting ports as to normally permit communication between all of said ports and being effective on introduction of iluid pressure into one of said inlet cavities to disconnect the iirst named port of the other inlet cavity from said other ports.

ROY S. SANFORD..

WILLIAM J. ANDRES. 

